A iStent® is a small (1 mm X 0.33 mm) device designed to fit into Schlemm’s canal to facilitate aqueous drainage from the anterior chamber. It is made of non-magnetic, surgical grade titanium; it is coated with heparin and comes preloaded in an inserter. There are two different orientations of iStent – one for each eye.1.

Q What are the indications for iStent?

A As approved by the FDA on June 25, 2012, the iStent “…is indicated for use in conjunction with cataract surgery for the reduction of intraocular pressure (IOP) in adult patients with mild or moderate open-angle glaucoma currently treated with ocular hypotensive medication.”2.2 The FDA also noted that “This option may be considered earlier in the disease process than some other types of surgical glaucoma treatments.”3.

Q Is iStent indicated for patients with glaucoma in the absence of cataract?

A No. The FDA approval specifies “in combination with cataract surgery”. All other uses are “off-label” and experimental or investigational. As a general rule, third party payers do not cover experimental and investigational procedures.

Q What CPT code describes implantation of iStent?

A A Category III CPT code, 0191T, established on July 1, 2008, applies. It reads, “Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the trabecular meshwork.”

Effective January 1, 2015, a second Category III code, 0376T, applies when more than one iStent is implanted in the same session. This code is defined as, “Insertion of anterior segment aqueous drainage device, without extraocular reservoir; internal approach, into the trabecular meshwork; each additional device insertion (list separately in addition to code for primary procedure).” This add-on code is only used in conjunction with 0191T.

A Yes, many commercial payers4. cover the iStent. Prior authorization should be obtained before scheduling a procedure whenever possible.

Q What is the global period for 0191T?

A As a Category III code, there is no specified global period for 0191T. The global period for concurrent cataract surgery is 90 days. As a practical matter, the known interval outweighs the unknown interval.

Q What does Medicare allow for 0191T?

A Payment rates vary by type of provider and site of service. In 2015, the Medicare allowed amounts for 0191T are:

Physician ………………… MAC discretion

ASC Facility Fee …………….. $1,711.53

HOPD Facility Fee …………… $3,121.34

Because the known values are higher than the allowed amounts for the concurrent cataract surgery, 0191T ought to be the primary procedure. These amounts are adjusted in each locality by local wage indices and are additionally subject to payer restrictions which can vary considerably.

For the add-on code, 0376T, there is likewise no set payment rate for physician services. For ASCs and HOPDs, 0376T is assigned zero ($0.00) dollars, which effectively bundles the add-on procedure with the primary procedure.

Q May gonioscopy be billed at the time of iStent implantation?

A No. Gonioscopy (CPT 92020) is required to implant the iStent. Because gonioscopy carries the “separate procedure” designation in CPT, it should not be billed when it is integral to the performance of another procedure.

Q Is there separate Medicare reimbursement for the iStent device?

A No. Medicare payment for the iStent glaucoma drainage device(s) is included in the facility reimbursement for APC 0673. On UB-04 claims, use revenue code 278, together with 0191T, to report the iStent procedure. If another iStent is used in the same operation, then include another line on the UB-04 claim for 0376T, again with revenue code 278. On the CMS-1500 form for ASCs, show 0191T and 0376T. The beneficiary may not be charged for the iStent device(s) since it is included in the facility fee.

For other payers, check your contracts with respect to prosthetic devices.

Q How should we bill if one surgeon removes the cataract and another implants the iStent?

A If both surgeons are part of the same group, then only a single claim is needed and the aggregate payment is made to the group. When the surgeons are not part of the same group, then separate claims are required.

Q Are there any NCCI edits or bundles for CPT 0191T?

A Yes; NCCI edits include, as expected, 66170, 66172, 66180 and 66183. Some other edits apply as well. In addition, all edits in place for the concurrent cataract procedure pertain.

Check NCCI edits periodically as they change quarterly. Most third party payers follow NCCI edits, but not all; check your payer contracts.

The reader is strongly encouraged to review federal and state laws, regulations, code sets (including ICD-9 and ICD-10), and official instructions promulgated by Medicare and other payers. This document is not an official source nor is it a complete guide on reimbursement. The reader is reminded that this information, including references and hyperlinks, changes over time, and may be incorrect at any time following publication.